Movement prediction for routing and medium access control in vehicular ad hoc networks

Menouar, Hamid

Thesis

Vehicular Ad-hoc Networks (VANETs) represent a rapidly emerging, particularly challenging class of Mobile Ad-hoc Networks (MANETs). VANETs are distributed, self-organizing communication networks built up from traveling vehicles, and are thus characterized by very high speed and limited degrees of freedom in nodes movement patterns. This makes the network topology changes very frequently and very rapidly, therefore more unstable when compared to MANETs, and existing protocols initially proposed for MANETs, mainly at the NET and the MAC layers, are not suitable for VANETs as they are. The vehicles' movement information assumes an important parameter which should be considered when designing any protocol for VANETs. In this work, we propose a concept which exploits the movement information of involved vehicles to predict the future status of the network topology. We call this concept MOPR (MOvement PRediction). Based on the prediction of the network topology evolution, the MOPRcross-layer architecture introduces a new metric called Link Stability (LS) metric to each communication link.This metric is then used at the NET layer to help the routing protocol in selecting the most stable routes, and at the MAC layer to help the MAC protocol to guarantee a better control between nodes when accessing the medium. Based on extensive simulations, we show the network performances improvements that MOPR can bring, mainly in case of highly dynamic networks. We present as well a preliminary prototype of MOPR. This prototype, even if still at an early stage, gives already an idea on the problems we may meet in implementing MOPR for realistic environments which will help us to improve our proposals